Search

Chronic social isolation (CSIS) generates two stress-related phenotypes: resilience and susceptibility. However, the molecular mechanisms underlying CSIS resilience remain unclear. We identified altered proteome components and biochemical pathways and processes in the prefrontal cortex cytosolic fraction in CSIS-resilient rats compared to CSIS-susceptible and control rats using liquid chromatography coupled with tandem mass spectrometry followed by label-free quantification and STRING bioinformatics. A sucrose preference test was performed to distinguish rat phenotypes. Potential predictive proteins discriminating between the CSIS-resilient and CSIS-susceptible groups were identified using machine learning (ML) algorithms: support vector machine-based sequential feature selection and random forest-based feature importance scores. Predominantly, decreased levels of some glycolytic enzymes, G protein-coupled receptor proteins, the Ras subfamily of GTPases proteins, and antioxidant proteins were found in the CSIS-resilient vs. CSIS-susceptible groups. Altered levels of Gapdh, microtubular, cytoskeletal, and calcium-binding proteins were identified between the two phenotypes. Increased levels of proteins involved in GABA synthesis, the proteasome system, nitrogen metabolism, and chaperone-mediated protein folding were identified. Predictive proteins make CSIS-resilient vs. CSIS-susceptible groups linearly separable, whereby a 100% validation accuracy was achieved by ML models. The overall ratio of significantly up- and downregulated cytosolic proteins suggests adaptive cellular alterations as part of the stress-coping process specific for the CSIS-resilient phenotype.

Two novel flexible counter electrodes (CEs) on Ti sheets using molybdenum and tungsten nitrides (Mo(2)N, W(2)N) as catalysts were synthesized and used in a dye-sensitized solar cell (DSC) system. High catalytic activity of the two nitride CEs for the reduction of triiodide were proved by cyclic voltammetry, electrochemical impedance spectroscopy and Tafel-polarization measurements. The DSCs based on Mo(2)N and W(2)N CEs achieved power conversion efficiencies of 6.38 and 5.81%, reaching 91 and 83% of the photovoltaic performance of the DSC using a Pt CE, respectively. This research paves a promising way to develop new CE catalysts and reduce the cost of DSCs.

Tungsten dioxide imbedded in mesoporous carbon (WO(2)-MC) was obtained by in situ synthesis and then introduced into dye-sensitized solar cells (DSCs) as a counter electrode (CE) catalyst. Catalytic activity for redox couple regeneration was improved significantly through combining high electrical conductivity and catalytic activity into one material, WO(2)-MC, in which WO(2) served as a catalyst and MC served as an electrical conductor. This has been proved by cyclic voltammetry (CV) and electrochemical impedance spectroscopy (EIS). The triiodide/iodide-based DSC using WO(2)-MC as CE showed a high power conversion efficiency (PCE) of 7.76%, which surpassed the performance of the DSC using traditional Pt CE (7.55%). In addition, the WO(2)-MC and WO(2) nanorods exhibited higher catalytic activity than Pt for the regeneration of a new organic redox couple, di-5-(1-methyltetrazole) disulfide/5-mercapto-1-methyltetrazole N-tetramethylammonium salt (T(2)/T(-)). The PCE of the T(2)/T(-)-based DSCs using WO(2)-MC, WO(2), and Pt were 5.22, 4.66, and 3.09%, respectively.